Generally a good film

Rating: Null/10 (11 November 2003)

First, I found it completely plausible that a virus might spread in this manner. Pneumonic plague kills in about 3 days and is symptomatic within hours of infection. So, in this film we are faced with a virus that is symptomatic within seconds and spreads by causing the infected to become so enraged that they will fight with and/or bite another individual. The virus is spread by blood to blood or saliva to blood contact.
This particular virus does not cause the infected to become the "undead" ... so it's not really a zombie movie ... although they are so driven to infect those who are unaffected, that one character is likely correct when he opines that the infected will starve to death after a time. (So will a victim of any plague if they are to sick to care for themselves and their disease doesn't kill them first.)
What we (and the main characters) don't know is how long the infected will survive and how much of the world (other than the British Isles) is dealing with the infection.
I found it interesting that the director shows us, on the one hand, the mindless infected causing pain and suffering without intending to do so, and, on the other hand, members of the military who justify the pain and suffering they are willing to inflict by telling themselves it's the only way for mankind to "survive." Procreation as a justification for rape. To me that is a profound idea that goes beyond the typical sci-fi film.
I also found it interesting that the viewer keeps seeing a sculputure of Lacoon and his sons being strangled by the serpent. It seems to be to be a classical reference to the beginning of the film when a lab worker tries to warn the people hoping to set the apes free from their misery that they will die and cause a disaster. Lacoon tried to do the same for the Trojans and the gods killed him for doing so ... it was part of the vengance of the gods that Troy was destroyed. Here you see the vengeance of the "gods" potentially destroying mankind, and a glimpse that the world might be better off for our absence.
As an aside, there is a scene in which a charater enters a church filled with corpses. I agree with earlier posters that most of the dead were probably suicides. Others may have died from starvation or the exhaustion caused by constant rage. In my opinion, the few infected that are there are likely asleep until the hero calls out. After all, they are merely infected... not dead. There's nothing to indicate that they don't sleep from time to time (even if it's just dropping from the exhaustion the rage virus must cause).
In any event, I found the film fascinating and will certainly watch it again.